Is it possible that you can turn off UEFI on a motherboard? More specifically the, ASROCK 990FX Extreme 9? The operating system ( Zorin 8.1/Linux) won't run if UEFI is on. I think? Could anyone please give me some clarification to this please?
In the bios, disabling secure boot, and enabling CSM or compatibility support mode disables uefi as far as the OS is concerned. You may need to Google around a bit... but that's what your looking for... CSM (compatibility support mode) hope this helps!
Your onboard sound is probably very good. Some people say you don't even need a sound card but I can hear a HUGE difference between my Auzentech X-Fi Forte and the Realtek onboard in my Sabertooth Z87.
However, your Realtek chip is likely newer so I can't be certain but I think a good sound card would still be better. It also makes little difference unless you have fairly good speakers (I have M-Audio AV40's). The BASS in particular is very important. I have 4" drivers in my stereo speakers. Many have 2" or less. Subwoofers are a different story but a big box doesn't mean high quality so read reviews if buying.
If using the DIGITAL output then it may make little sense to get an onboard sound card as the Speaker unit is converting and amplifying the signal so you don't have to worry about noise interference and the quality of the OPAMP and amplification setting on the motherboard to output a quality VOLTAGE signal through the 3.5mm cable.
There are still a few older games I play that I enable in Audigy to get the best quality (for the EAX extensions that stopped being supported after XP). They include:
Call of Duty 1
Dreamfall (settings need to be set to 4, 5, 128)
FEAR (if playing this game Google how to disable USB devices or performance sucks)
Neverwinter Nights 2
Star Wars KOTOR (great game. Has a resolution fix at WSGF)
Witcher 1 (you also need to force VSYNC on for this game using the proper EXE file which I think is in a subfolder)
Vampire Masquerade Bloodlines